Heat insulating material



HARVEY D. GEYER, ARTHUR H. AND

OHIO, ASSIGNORS TO THE INLAND MANUFACTURING Patented Oct. 2t), 1931 UNITED STATES PATENT o FIcE a conronarron or DELAWARE JACOB O, HOUSE'KEEPER, DAYTON, COMPAIN Y, OI DAYTON, OHIO,

. ans-r menu-nine MATERIAL Ho Drawing.

This invention relates to an improved heat insulating material composed largely of shredded particles of highly blown vulcanized, rubber compound, and the method of tin ' resisting which will not rot aklng the same. 7 An object of the invention is to provide an 'elficient and-economically made heat insulat ing this invention at the present time.

Attempts have been made to make and use slabs of. blown or cellular hard rubber compound as a substitute for the well hown cork boardheat insulation. Heretofore, so far as lmown, all such attempts have produced a 1 cellular material which has a much greater specific gravity than cork-board and hence such attempts have not been coe'rcially successful due chiefly, to the objectionable heavy weight of the insulating material and.

the resulting" high cost thereof.

' By this present invention a suitable uncured rubber compound is first provided which is capable of an exceedin ly high blow (increase in volume due to fhrmation of gas cells therein) during vulcanization due to the gasifying of the blowing agent which is compounded therein. Blowihg agents are well known to rubber com ounding experts and need not be speciiie here- Such excessive blowing of vulcanized rubber compounds has not been heretofore deemed of any commercial value due to the impossib' 'ty of controlling the final shape and size of the hard vulcanized blown rubher piece. The greater. the degree of blowing or the increase in volume of the material durmg'vulcanization, the greater will be the disto fen and irregularity in 'shap e ozt the ding,

Applicatloir filed m 21, 1929. sci-1n racemes.

final hard vulcanizedpiece of material. In themethod of this invention the distortion or irregularity-of shape of the highly blown vulcanized hard rubber isnot objectionable and no attempt is made to control same, since by permitting free expansion on all sides bf I the piece during vulcanization agreater blow may be obtained without difliculty; Then the highly irregular and non-uniform slabs or pieces of vulcanized cellularhard or stiff rubber compound are broken upinto relatively small irregular particles by means of a suitable shredding device. After shredthis broken material is treated with a suitable binder,

200 F., and the mass of heated lown rubber particles and binder is shaped up to the desired slab or other form in shaping molds and permitted to set and harden.

Preferably ering is provided on the top and bottom sides of the formed slabs to give the following advantages: the molded slab may be more easily such as a molten bituminous binder having a melting oint around To; some sort of outer surface covfreed from the shaping mold; a smoother and more Water-proof surface is provided on the slab; the slab may be more, conveniently I handled and more accurately 'cut and he ted in place when used to cover heat-insulatin walls in, the manner corkcard are ordinarily used. For such surface covering a heavy paper previously coated on one side with an asphalt material may be used, this paper being preferably laid in the shaping mold cavity with rial to be molded and thus caused to adhere firmly to the stead of paper, the shaped slabs may be coated with a thin coating of rubber latex composition, or rubber latex and basein glue cement, or bakelite cement, or rubber cement,

that slabs of 35 the coated side thereof faced toward the cellular matemolded slab of cellulargnaterial Y -when removed from theshaping mold. inw by any suitable means which will be obvious to those skilled in the art, suchas by spraying such fluid substances upon the formed slabs and drying or hardening suchcoating.

As atypical example of a high-blowing rubber compound which may be satisfac loo torily used with the method of this invention as above described, the following is given:

Diphenyl guanidine 0. 15

This compound may be mixed on an ordinary rubber mixing mill or in a Banburlyi type mixer to form a batch of uncured stoc which is preferably first aged for 24 hours prior to vulcanizing in an open steam vulcanizer for two hours at fifty pounds of steam pressure, or 298 F. The rubber compound to be used with this invention is preferably chosen to give maximum blow or cellular structure together with stiffness of structure without any attempt to control the shape or size of the vulcanized pieces. These vulcanized pieces are then broken or otherwise divided into small particles which may vary considerably in size, though preferably these particles should range from five to ten cu. centimeters each and with the least amount of pulverization possible.

A bituminous binder is preferably used as the adhesive means for the cellular rubber particles. This binder may be added to the shredded rubber particles in a molten condit1on and sprayed thereon with a heated spray gun, or y an other suitable means WlllCh may be readi y devised. A bituminous material which has been found very satisfactory for this use is medium paralite ilfiVlIlg the following physical characteris- 1cs: goggeljting pt. (ball and ring method)-190 Penetration at 32 F.not less than 6.

Penetration at 77 F .11 to 15. 30Penetration at 115 F.not more than 1 0%pecific gravity at F.not less than Flash pt.not less than 450 F. Solubility in C S --not less than 99%. 5-h'r. loss' at 325 F.not more than 0.2%. The above special type of material is not necessary, as many other types of bituminous binders can be used, an important requisite being that the binder should not be brittle when cold. I

The mass of shredded cellular rubber after 'being'treated with the binder should be warmed before it is inserted into shaping molds in order to render the binder more fluid and give a certain amount of plasticity to the mass to facilitate the proper filling of the shaping molds. An ordinary size 'of 0 such molded slab is 2% inches by 24 inches by 24 inches. The slab is preferably allowed to cool within the shaping mold but without pressure thereupon.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

' What is claimed is as follows:

1. The steps in'the method of making heat insulating material comprising: providin a cellular rubber composition structure, dividing said cellular structure into relatively small particles, and then binding said particles together with a suitable binder.

2. The steps in the method of making heat insulating material comprising: providing a cellular rubber composition structure, dividing said cellular structure into relatively small particles, applying a binding material to said particles and then shaping forms of I insulating material from said cellular par-' ticles and applied binder.

3. The steps in the method of making heat insulating material comprising: providing a cellular rubber composition structure,dividing said cellular structure into relatively small particles, spraying said cellular particles with a suitableEbinder in fluid state, and then molding forms of insulatin material from said cellular particles an binder.

4;. The steps in the method of makin' I heat insulating material comprising: provi g a cellular rubber composition structure, dividing said cellular structure into relatively small particles,spraying said cellular particles with a molten binder to give an adhering plastic mass, and then shaping saldmass to the desired form before said binder hardens.

5. The steps in the method of making heat insulating material comprising: providing irregular shaped pieces of highly blown vulcanized cellular rubber composition, dividing said irregular shaped pieces into relat vely small particles, applying a fluid binding applied ion material to said particles to form an adherform and permitting said binder to harden.

7. The steps in the method of making heat insulating material com rising: providing irregular shaped pieces 0 highly blown vulcanized cellular rubber composition, shredding said blown rubber pieces into relativel small particles, applying a molten bituminous binder to said particles, and then molding the resulting mass into desired forms.

8. The method of making heat insulating slabs, comprising: vulcanizing a rubber composition into a highly blown cellular structure' without regard to the uniformity of the resulting shape or size of such cellular structure, dividing said cellular structure into relatively small particles, applying a binder material to said particles, and then shaping the mass of said particles and binder into the desired slab form and permitting said binder to harden.

9. The method of making heat insulating slabs, comprising: vulcanizing a rubber composition into a highly blown cellular structure without regard to the uniformity of the resulting shape or size of such cellular structure, dividing said cellular structure into relatively small particles, applying a molten bituminous binder to said particles to form an. adhering mass, I and then molding said mass into desired form in shaping molds and permitting the binder to set and harden.

10. As a new article-of manufacture,.heat insulating material comprising: shredded particles of highly blown vulcanized rubber compound held bound together with an ad hering binder. v

In testimony whereof we hereto aflix our signatures.

HARVEY D. GEYER. ARTHUR H. FLOWER. v. JACOB G. HOUSEKEEPER- 

